The pressure ultimately became even more than German Defense Minister Karl-Theodor zu Guttenberg could withstand. On Tuesday, almost two weeks after news broke that he had plagiarized large portions of his doctoral dissertation, Guttenberg announced his resignation.

"I am going not only because of my faulty dissertation, although I understand that this would be reason enough from the perspective of academia," the departing minister said. "The reason is particularly to be found in the question as to whether I can fulfill my responsibilities."

"I was always ready to fight," Guttenberg said at the very end of his statement. "But I have reached the limits of my strength."

The move comes despite repeated assurances from the chancellor that Guttenberg had her full support. But recent days have seen an increasing number of politicians from Merkel's governing coalition voicing their disdain for Guttenberg and frustration at the chancellor's handling of the affair. Furthermore, there was growing concern that the scandal could further erode support for Merkel's conservatives ahead of several important regional elections this year.

According to SPIEGEL ONLINE sources, Guttenberg made his decision on Monday and informed the chancellor.

'A Nail in the Coffin of Confidence in Our Democracy'

Indeed, Monday's papers were full of quotes from senior conservative politicians questioning whether Guttenberg should remain in office. Parliamentary President Norbert Lammert of Merkel's Christian Democratic Union (CDU) party even went so far as to say that the affair was "a nail in the coffin of confidence in our democracy."

Senior members of the Christian Social Union (CSU), the Bavarian sister party to the CDU, of which Guttenberg is a member, likewise began withdrawing support for Guttenberg. Former party head Günther Beckstein told the newsweekly Stern that the affair "damages both the CSU and Guttenberg himself." Another CSU member, who preferred to remain anonymous, told Stern that Guttenberg was a "dandy, not a politician."

Also on Monday, Martin Neumann, parliamentary spokesman for academic issues for the business-friendly Free Democratic Party (FDP), Merkel's junior coalition partner, said Guttenberg should resign. "Should he continue to allow the circumstances of his dissertation to remain so unclear," Neumann told the Financial Times Deutschland newspaper, "I think that he, as minister and as the top official of two Bundeswehr universities, is no longer acceptable."

By the end of last week, it had become clear that Guttenberg's dissertation contained dozens of passages that had been copied word-for-word from previously published works without adequate citation. He also included several pages from research notes he requested from parliamentary research assistants. It is not allowed for parliamentarians to use Bundestag research assistants for private business.